But most of the time, the “cost” of renewable is undefined, because you simply can't use it: you need the grid to compensate for the intermittent generation. No battery won't be enough unless you are in a really specific situation:

- hydroelectric source available, in which case, it's a no-brainer, but most of those sites are already exploited (hydroelectric power was historically the first to come).

- if tpu want to go for solar power, you need tropical or subtropical area, where you have the same amount of sun during the whole year. Otherwise you either need to have batteries able to sustain the whole winter, or dimension your system for winter (which dramatically increases the cost and you end up with a lot of unused power during summertimes).

- for wind power, you need a regularly windy area (the top of a hill, the middle of the sea) and batteries because the world best wind power sites still don't produce every days (storms means shutdown for instance).

If you don't have the perfect spot for one of those, the batteries aren't even a solution[1], because you'd need something like two to four weeks of power in terms of storage…

Or, you could go for a mix between fossil fuel and renewable, which is why the oil and gas industry is making a big push towards renewables …